2 files changed, 33 insertions, 2 deletions

diff --git a/sound/pci/hda/hda_codec.h b/sound/pci/hda/hda_codec.h
index 2b5d19e48a27..ab2a444ba501 100644
--- a/sound/pci/hda/hda_codec.h
+++ b/sound/pci/hda/hda_codec.h
@@ -361,6 +361,7 @@ struct hda_codec {
         unsigned int epss:1;            /* supporting EPSS? */
         unsigned int cached_write:1;    /* write only to caches */
         unsigned int dp_mst:1; /* support DP1.2 Multi-stream transport */
+        unsigned int dump_coef:1; /* dump processing coefs in codec proc file */
 #ifdef CONFIG_PM
         unsigned int power_on :1;       /* current (global) power-state */
         unsigned int d3_stop_clk:1;     /* support D3 operation without BCLK */
diff --git a/sound/pci/hda/hda_proc.c b/sound/pci/hda/hda_proc.c
index a8cb22eec89e..ce5a6da83419 100644
--- a/sound/pci/hda/hda_proc.c
+++ b/sound/pci/hda/hda_proc.c
@@ -24,9 +24,14 @@
 #include <linux/init.h>
 #include <linux/slab.h>
 #include <sound/core.h>
+#include <linux/module.h>
 #include "hda_codec.h"
 #include "hda_local.h"
 
+static int dump_coef = -1;
+module_param(dump_coef, int, 0644);
+MODULE_PARM_DESC(dump_coef, "Dump processing coefficients in codec proc file (-1=auto, 0=disable, 1=enable)");
+
 static char *bits_names(unsigned int bits, char *names[], int size)
 {
         int i, n;
@@ -488,14 +493,39 @@ static void print_unsol_cap(struct snd_info_buffer *buffer,
                     (unsol & AC_UNSOL_ENABLED) ? 1 : 0);
 }
 
+static inline bool can_dump_coef(struct hda_codec *codec)
+{
+        switch (dump_coef) {
+        case 0: return false;
+        case 1: return true;
+        default: return codec->dump_coef;
+        }
+}
+
 static void print_proc_caps(struct snd_info_buffer *buffer,
                             struct hda_codec *codec, hda_nid_t nid)
 {
+        unsigned int i, ncoeff, oldindex;
         unsigned int proc_caps = snd_hda_param_read(codec, nid,
                                                     AC_PAR_PROC_CAP);
+        ncoeff = (proc_caps & AC_PCAP_NUM_COEF) >> AC_PCAP_NUM_COEF_SHIFT;
         snd_iprintf(buffer, "  Processing caps: benign=%d, ncoeff=%d\n",
-                    proc_caps & AC_PCAP_BENIGN,
-                    (proc_caps & AC_PCAP_NUM_COEF) >> AC_PCAP_NUM_COEF_SHIFT);
+                    proc_caps & AC_PCAP_BENIGN, ncoeff);
+
+        if (!can_dump_coef(codec))
+                return;
+
+        /* Note: This is racy - another process could run in parallel and change
+           the coef index too. */
+        oldindex = snd_hda_codec_read(codec, nid, 0, AC_VERB_GET_COEF_INDEX, 0);
+        for (i = 0; i < ncoeff; i++) {
+                unsigned int val;
+                snd_hda_codec_write(codec, nid, 0, AC_VERB_SET_COEF_INDEX, i);
+                val = snd_hda_codec_read(codec, nid, 0, AC_VERB_GET_PROC_COEF,
+                                         0);
+                snd_iprintf(buffer, "    Coeff 0x%02x: 0x%04x\n", i, val);
+        }
+        snd_hda_codec_write(codec, nid, 0, AC_VERB_SET_COEF_INDEX, oldindex);
 }
 
 static void print_conn_list(struct snd_info_buffer *buffer,